Italian Patent Application No. 67224-A/88 (U.S. Pat. No. 5,042,287, is the U.S. counterpart) discloses a manipulator device for a sheet metal bending press, comprising the following:
a main manipulator unit provided with at least one element for gripping a sheet metal piece, which is movable in a manipulation space in front of a loading zone of the press and is arranged to move sheet metal pieces during an automatic bending cycle, and
an auxiliary manipulator unit provided with gripper means rotatable about an axis perpendicular to the bending line and arranged to grip a sheet metal piece and to turn it over about the said axis.
During a bending cycle carried out by means of this known device, there are many phases in which the manipulator device is engaged in moving a piece of sheet metal while the press is inoperative. The phases in which the press is inoperative are, for example, those in which the manipulator device discharges a finished piece and takes up a new flat metal sheet, as well as those in which the piece is overturned by means of the auxiliary manipulator unit.